The present invention concerns a semiconductor device and a method of manufacturing the semiconductor device and, it particularly relates to a semiconductor device having a structure of stacking an aluminum oxide film over a Ga-containing nitride semiconductor layer, and a method of manufacturing the semiconductor device.
When a transistor is formed by using a Ga-containing nitride semiconductor layer, candidates for the materials of gate insulating film includes various substances.
For example, Japanese Unexamined Patent Application Publication No. 2005-183597 describes investigation for the use of nitrogen-containing aluminum oxide layer as a gate insulating film.
Japanese Unexamined Patent Application Publication No. 2010-45308 describes that a material containing Al in the composition and having a spinel structure is used as a gate insulating film. As the material, MgAl2O4, MnAl2O, CoAl2O4, and NiAl2O4 are shown as examples.
Japanese Unexamined Patent Application Publication No. 2004-273630 describes that an AlGaN layer is used as a gate insulating film.
Japanese Unexamined Patent Application Publication No. 2007-235000 describes that a silicon nitride film, a silicon oxide film, or a silicon oxynitride film is used as a gate insulating film.